1. Field of the Invention
This invention generally relates to aircraft and particularly relates to flight control of aircraft without external, aerodynamic control surfaces.
2. Description of the Prior Art
In a typical aircraft, moveable aerodynamic control surfaces are installed on wings or other portions of the aircraft that are exposed to the airflow during flight. These control surfaces are moveable relative to the aircraft and include, for example, ailerons, trim tabs, canards, and rudders. These surfaces use aerodynamic effects to cause moments in the yaw, pitch, and roll directions for controlling the orientation of the aircraft or for stabilizing the aircraft during flight. Moveable, external control surfaces are complicated, requiring many parts and adding to the weight of the aircraft. Another characteristic of external control surfaces which may be undesirable is that they create drag in operation. Also, the radar cross-section of an aircraft increases when the control surfaces are displaced from their nominal positions, reducing the stealth characteristics of the aircraft.
Modern aircraft advances include vectored thrust and internal engines. Vectored thrust is used in vertical takeoff and landing (VTOL) or short-takeoff and vertical landing (STOVL) applications and for producing quicker maneuvers or allowing steeper angles of attack. Thrust vectoring is done externally, generally by using a rotating or articulating nozzle.
In some military applications, engines are installed deep within the body of the aircraft. Though this tends to reduce the external heat signature and reduce the exposed surfaces that would increase the radar cross-section of the aircraft, it is more difficult to implement thrust vectoring.
An apparatus and method for flight control of an aircraft provides a body with adjustable intake ports ducting air into an internal intake manifold. Adjusting the openings of the intake ports changes the amount of air flowing over the surfaces surrounding the intakes, changing the amount of lift created by those surfaces. The intake manifold feeds air to at least one engine, and an exhaust manifold communicates the exhaust of the engine to exhaust exit ports. The exhaust manifold contains a plurality of moveable components that direct exhaust within the exhaust manifold and to particular exhaust exit ports for producing various levels of force imbalance among the exit ports. A compressor powered by the engine provides air to bleed-air ports on the wings for creating roll moments. Varying lift on the forward surfaces with the intake ports, vectored exhaust, and bleed air are used to control and stabilize the aircraft during flight, obviating the need for aerodynamic control surfaces.